Orthodontic bracket

ABSTRACT

Orthodontic brackets that can accurately be mounted to the surface of teeth to effectively perform orthodontic treatment. The orthodontic bracket according to the present invention is characterized in that, a marker is provided on at least a portion of an outline that is generated by crossing a plane including a longitudinally extending center line, on a base of an archwire slot, of the archwire slot and vertical to the base of the archwire slot, and an outer surface of the body with each other. With this bracket, coinciding the marker provided on at least a portion of the outline to the mid-transverse plane of a tooth, to which the bracket is bonded, allows the base point of the bracket to be positioned on the mid-transverse plane, further, coinciding the center of the bracket to the FACC causes the bracket to accurately be positioned on the tooth to be treated, resulting in effective orthodontic treatment. The marker can be selected from a protrusion, a projection, a slit and a notch.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to orthodontic brackets that are easilypositioned at orthodontically correct locations on the patient's teethto effectively perform orthodontic treatment.

2. Description of the Related Art

In orthodontic treatment, orthodontic brackets made of metal or the likeare bonded to the patient's teeth through bonding agent; the orthodonticbrackets are fastened by a thin archwire; and an external force isapplied to the orthodontic brackets through the archwire to move theteeth subjected to treatment to correct locations.

When an orthodontic bracket is bonded to the patient's tooth, as shownin FIG. 10, a vertical center line 85 of a bracket 84 should beoverlapped with a facial axis of a clinical crown (hereinafter referredto as “FACC”) 81, and a center (base point) 86 b of a base 86 a of anarchwire slot 86 should be coincided with a mid-transverse plane 82. Ifthe bracket 84 is not positioned properly as described above, load of anarchwire cannot be applied properly to the tooth through the bracket 84,resulting in insufficient orthodontic treatment.

In order to overlap the vertical center line of the bracket to the FACC,a variety of brackets with markers have been used. Meanwhile, in orderto coincide the base point of the bracket to the mid-transverse plane ofthe tooth, for example, a gage partially fixed to an archwire slot ofthe bracket is used to bond the bracket to the tooth with the distancebetween the occlusal plane of the tooth and the slot being measured bythe gage. However, since the base point of the bracket and the surfaceof the tooth are apart from each other, and manners abutting the gage tothe teeth should be changed in accordance with the position of the toothin a row of the patient's teeth, it is not easy to coincide the basepoint of the bracket to the mid-transverse plane of the tooth with thegage.

On the other hand, Japanese Patent Publication (Unexamined) No. Heisei8-112293 discloses an orthodontic bracket that can be bonded to acorrect position, which is parallel to the FACC and the occlusal plane.This bracket is provided with a visible standard line, which is to beparallel to the FACC, on the center line of a pair of tiewings, andanother visible standard line, which is to be parallel to the occlusalplane, on a slot line crossing the former standard line. Then,orthodontists can adjust the location of the bracket while positivelyutilizing the standard lines.

As described above, when a bracket is mounted to a tooth, it isnecessary to coincide the vertical center line of the bracket to theFACC as well as the base point to the mid-transverse. But, it is noteasy to do so with the above-mentioned gage. With the bracket shown inthe above document, standard lines are provided on the center line of apair of tiewings and on the slot line only, so that it is not easy tocoincide the base point of the bracket and the mid-transverse plane ofthe tooth with each other.

Especially, as illustrated in FIG. 11, when a torque-in-face-typebracket is used, in order to coincide a base point 98 of a bracket 90 toa mid-transverse plane 92 of a tooth 96 to be treated, it is necessaryto coincide a target point 100 that is generated by crossing a line,which passes the base point 98 of the bracket 90 and vertical to a base91 a of an archwire slot 91, and a base 99 a of a body 99, to afacial-axis point (hereinafter referred to as “FA point”) 94 where theFACC of the tooth 96 and the mid-transverse plane 92 cross with eachother. However, since the target point 100 and a center 99 b of the base99 a of the body 99 are remarkably apart from each other, it is not easyto coincide the target point 100 of the bracket 90 to the FA point 94,in its turn, it is not easy to coincide the base point 98 of the bracket90 to the mid-transverse plane 92 of the tooth 96.

SUMMARY OF THE INVENTION

It is therefor the object of the present invention to provide bracketsin which a vertical center line of the bracket can easily be coincidedto the FACC, and the base point of the bracket can easily be coincidedto the mid-transverse plane, resulting in effective orthodontictreatment.

To accomplish the above objective, an orthodontic bracket according tothe present invention is characterized in that, a marker is provided onat least a portion of an outline that is generated by crossing a planeincluding a longitudinally extending center line, on a base of anarchwire slot, of the archwire slot and vertical to the base of thearchwire slot, and an outer surface of the body with each other.

With the above orthodontic bracket according to the present invention,coinciding the marker provided on at least a portion of the outline tothe mid-transverse plane of a tooth, to which the bracket is bonded,allows the base point of the bracket to be positioned on themid-transverse plane, further, coinciding the center of the bracket tothe FACC causes the bracket to accurately be positioned on the tooth tobe treated, resulting in effective orthodontic treatment.

In the afore-mentioned bracket according to the present invention, themarker may be selected from a protrusion, a projection, a slit and anotch.

Further, an orthodontic bracket according to the present invention ischaracterized in that, a through hole penetrates a body from a base ofthe body to an outer surface of the bracket along a line passing througha point that is generated by crossing a line, which is generated bycrossing a plane including a longitudinally extending center line, on abase of an archwire slot, of the archwire slot and vertical to the baseof the archwire slot, and the base of the body, and a plane vertical tothe center line of the archwire slot and dividing the body exactly intotwo parts.

With the above orthodontic bracket according to the present invention,using a needle-like jig, the FA point of the tooth to be treated and thetarget point for positioning of the bracket can directly be coincidedwith each other, which is effective especially in indirect method, inwhich a bracket is preliminarily bonded on a model of the patient's rowof teeth at a position where the bracket should be mounted, and then,the bracket is properly transported in the oral cavity of the patientand is bonded to the patient's tooth.

The orthodontic bracket described above may further comprises a markerprovided on at least a portion of an outline that is generated bycrossing the plane including the longitudinally extending center line,on the base of the archwire slot, of the archwire slot and vertical tothe base of the archwire slot, and an outer surface of the body witheach other. With this construction, directly coinciding the FA point ofthe tooth to be treated and the target point for positioning of thebracket with each other, and further coinciding the marker to themid-transverse plane of the tooth, to which the brackets is mounted,causes the bracket to remarkably accurately be positioned on the toothto be treated with ease. And, the marker can be selected from aprotrusion, a projection, a slit and a notch.

Still further, an orthodontic bracket according to the present inventionis characterized in that, one of a projection and a concave portion isprovided at a point that is generated by crossing a line, which isgenerated by crossing a plane including a longitudinally extendingcenter line, on a base of an archwire slot, of the archwire slot andvertical to the base of the archwire slot, and the base of the body, anda plane vertical to the center line of the archwire slot and dividingthe body exactly into two parts.

With the above orthodontic bracket according to the present invention,engaging the projection or the concave portion at the target point ofthe base of the body to the concave portion or the projection, which isformed on the FA point of the tooth to be treated in advance, allows theFA point of the tooth to be treated and the target point for positioningof the bracket to directly be coincided with each other, whichespecially effective in indirect orthodontic treatment.

The orthodontic bracket described above may further comprises a markerprovided on at least a portion of an outline that is generated bycrossing the plane including the longitudinally extending center line,on the base of the archwire slot, of the archwire slot and vertical tothe base of the archwire slot, and an outer surface of the body witheach other. With this construction, directly coinciding the FA point ofthe tooth to be treated and the target point for positioning of thebracket with each other, and further coinciding the marker to themid-transverse plane of the tooth, to which the brackets is mounted,causes the bracket to remarkably accurately be positioned on the toothto be treated with ease. And, the marker can be selected from aprotrusion, a projection, a slit and a notch.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more apparent from the ensuringdescription with reference to the drawings, wherein:

FIGS. 1A to 1C show an orthodontic bracket according to the firstembodiment of the present invention, in which FIG. 1A is a front view,FIG. 1B a plan view and FIG. 1C a side view;

FIG. 2 is a perspective view of the orthodontic bracket shown in FIGS.1A to 1C;

FIGS. 3A to 3C are drawings for explaining a manner to mount the bracketshown in FIGS. 1A to 1C to a tooth, in which FIG. 3A is for explaining astandard line and a standard point of the tooth, FIG. 3B is a plan viewfor explaining the manner to mount the bracket to the tooth, and FIG. 3Cis a side view of the bracket and the tooth shown in FIG. 3B;

FIGS. 4A to 4C show an orthodontic bracket according to the secondembodiment of the present invention, in which FIG. 4A is a front view,FIG. 4B a plan view and FIG. 4C a side view;

FIG. 5 is a drawing for explaining the usage of the bracket shown inFIGS. 4A to 4C;

FIGS. 6A to 6C show an orthodontic bracket according to the thirdembodiment of the present invention, in which FIG. 6A is a front view,FIG. 6B a plan view and FIG. 6C a side view;

FIG. 7 is a drawing for explaining the usage of the bracket shown inFIGS. 6A to 6C;

FIGS. 8A to 8C show an orthodontic bracket according to the forthembodiment of the present invention, in which FIG. 8A is a front view,FIG. 8B a plan view and FIG. 8C a side view;

FIG. 9 is a drawing for explaining the usage of the bracket shown inFIGS. 8A to 8C;

FIGS. 10A to 10D are drawings for explaining a manner to mount aconventional bracket to a tooth, in which FIG. 10A is for explaining astandard line and a standard point of the tooth, FIG. 10B is a plan viewfor explaining the manner to mount the bracket to the tooth, FIG. 10C isa side view of the bracket and the tooth shown in FIG. 10B, and FIG. 10Dis an enlarged view showing the bracket on the tooth; and

FIG. 11 is a schematic view for explaining a manner to mount aconventional torque-in-face-type bracket to a tooth.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Now, preferred embodiments of the present invention will be explainedwith reference to drawings.

FIGS. 1A to 1C and FIG. 2 show an orthodontic bracket according to thefirst embodiment of the present invention. This bracket 1 is providedwith tiewings 3 (3A, 3B) and archwire slots (hereinafter referred to as“slots”) 4 (4A, 4B) on a body 2, and the bases 4 a of the slots 4 andthe base 2 a of the body 2 are parallel with each other, that is, astandard bracket. The body 2 includes a pad portion, which is the samein other embodiments described below.

The first slit 5 as a marker is formed along an outline generated bycrossing a plane including a center 2 b of a base 2 a of the body 2 ofthe bracket 1 and vertical to a longitudinal direction of the slot, andthe outer surface of the body 2. The marker of the first slit 5 is usedto coincide a vertical center line of the bracket 1 to the FACC of atooth. This marker is the same as formed in conventional brackets.

In addition to the first slit 5, the second slits 6 (6A, 6B) as markersare formed along an outline generated by crossing a plane including alongitudinally extending center line 4 b, on the base 4 a of thearchwire slot 4, of the archwire slot 4 and vertical to the base 4 a ofthe archwire slot 4, and the outer surface of the body 2 with eachother, and along a line connecting ends of the outline and ends of thecenter lines 4 b of the slots 4 with each other on rising portions ofthe tiewings 3. The markers of the second slits 6 are a specialcharacter of the present invention, and are used to coincide these slits6 to the mid-transverse plane of a tooth to accurately coincide the basepoint 4 c of the bracket 1 to the mid-transverse plane of the tooth.

Next, the usage of the bracket 1 will be explained with reference toFIGS. 3A to 3C. In these figures, the tooth 10 is illustrated withoutany angulations and torque as a matter of convenience.

When the bracket 1 is mounted to the tooth 10, it is necessary tocoincide the vertical center line of the bracket 1 to the FACC 11 of thetooth 10, and the base point 4 c of the bracket 1 to the mid-transverseplane 12 of the tooth. Therefore, as illustrated in FIG. 3B, with theeyes, the first slit 5 of the bracket 1 is overlapped to the FACC 11,and the second slits 6 (6A, 6B) are coincided to the mid-transverseplane 12 of the tooth, which allows the bracket 1 to accurately bebonded to a proper position of the tooth 10 with ease. As a result, theorthodontic treatment can effectively be carried out.

Next, the second embodiment of the present invention, in which theso-called torque-in-face-type bracket is used, will be explained withreference to FIGS. 4A to 4C and FIG. 5.

The torque-in-face-type bracket is, as shown in FIGS. 4C and 5,characterized in that the bracket 21 is provided with tiewings 23 (23A,23B); bases 24 a of slots 24 (24A, 24B) and a base 22 a of a body 22 arenot parallel with each other; and a plane including a longitudinallyextending center line 24 b, on the base 24 a of the archwire slot 24, ofthe archwire slot 24 and vertical to the base 24 a of the archwire slot24 does not pass through the center 22 b of the base 22 a of the body22. Therefore, as shown in FIG. 11, the target point 100 of the bracket90, which should be coincided with the FA point 94 of the tooth 96, andthe center 99 b of the base 99 a of the body 99 are remarkably apartfrom each other, so that it is not easy to coincide the base point 98 ofthe bracket 90 to the a mid-transverse plane 92 of the tooth 96.

With the bracket 21 of the present invention, in addition to the firstslit 25 like the first slit 5 in the above first embodiment, the secondslits 26 (26A, 26B) as markers are formed along an outline that isgenerated by crossing a plane including the longitudinally extendingcenter line 24 b, on the base 24 a of the archwire slot 24, of thearchwire slot 24 and vertical to the base 24 a of the archwire slot 24,and an outer surface of the body 22 with each other, so that, as shownin FIG. 5, coinciding end portions 26 a of the slits 26 situated at edgeportions of the body 22 to the mid-transverse plane 38 of the tooth 39allows the base point 24 c of the bracket 21 to be coincided to themid-transverse plane 38 of the tooth 39, resulting in effectiveorthodontic treatment.

Next, the third embodiment of the present invention, in which theso-called torque-in-base-type bracket is used, will be explained withreference to FIGS. 6A to 6C and FIG. 7.

The torque-in-base-type bracket is, as shown in FIGS. 6C and 7,characterized in that the bracket 41 is provided with tiewings 43 (43A,43B); bases 44 a of slots 44 (44A, 44B) and a base 42 a of a body 42 arenot parallel with each other; and a plane including a longitudinallyextending center line 44 b, on the base 44 a of the archwire slot 44, ofthe archwire slot 44 and vertical to the base 44 a of the archwire slot44 passes through the center 42 b of the base 42 a of the body 42.

With this bracket 41 of the present invention, in addition to the firstslit 45 like the first slit 5 in the above first embodiment, the secondslits 46 (46A, 46B) as markers are formed along an outline that isgenerated by crossing a plane including the longitudinally extendingcenter line 44 b, on the base 44 a of the archwire slot 44, of thearchwire slot 44 and vertical to the base 44 a of the archwire slot 44,and an outer surface of the body 42 with each other, so that, as shownin FIG. 7, coinciding end portions 46 a of the slits 46 situated at edgeportions of the body 42 to the mid-transverse plane 58 of the tooth 59allows the base point 44 c of the bracket 41 to be coincided to themid-transverse plane 58 of the tooth 59, resulting in effectiveorthodontic treatment.

The slits 5, 6, 25, 26, 45 and 46 as markers should not be formed on theoverall outlines, but those may be placed near the edge portions only.Further, the markers are not limited to slits, but protrusions,projections and notches may be used. Besides the slits 5, 6, 25, 26, 45and 46 as markers, which are obtained by directly machining brackets,markers painted on the outer surface of brackets, which are utilized toposition the brackets and are rubbed out after the positioning, may beincluded in the scope of this invention.

In addition, not only markers for positioning directly applied tobrackets as described above, but also a jig mounted to a slot of abracket and functioning, with a part of the jig, in the same manner asthe slit or the like on at least a portion of the outline may beincluded in the scope of the present invention.

Next, the forth embodiment of the present invention, which is especiallysuitable for the indirect boding method, will be explained. In thismethod, a bracket is preliminarily bonded on a model of the patient'srow of teeth at a position where the bracket should be mounted, andthen, the bracket is properly transported in the oral cavity of thepatient and bonded to the patient's tooth.

As illustrated in FIGS. 8A to 8C, the bracket 61 is constructed suchthat a through hole 62 is drilled so as to penetrate the body 22 fromthe base 22 a of the body 22 to the outer surface of the bracket 61along a line passing through a point (target point) 27 that is generatedby crossing a line, which is generated by crossing a plane including thelongitudinally extending center line 24 b, on the base 24 a of thearchwire slot 24, of the archwire slot 24 and vertical to the base 24 aof the archwire slot 24, and the base 22 a of the body 22, and a planevertical to the center line 24 b of the archwire slot 24 and dividingthe body 22 exactly into two parts.

To use this bracket 61, as shown in FIG. 9, a needle-like jig 71 isinserted into the through hole 62 of the bracket 61, and the tip of thejig 71 is fixed to an FA point 73, which is marked in advance on a tooth74 on a model of a row of teeth to position the target point 27 on thebase 22 a of the body 22, and then, as described above, the second slits26 of the bracket 61 and the mid-transverse plane 38 of the tooth 74 arecoincided with each other to position the bracket 61 to the tooth 74.After that, with the transfer tray, registered in Japanese Utility ModelNo. 3097069 by the present applicant, or the like, the bracket 61 isaccurately positioned on the patient's tooth with ease.

Although, in the fourth embodiment described above, the through hole 62is drilled on the body of the torque-in-face-type bracket 21, thethrough hole 62 may be applied to the standard bracket shown in FIGS. 1Ato 1C and FIG. 2, and the torque-in-base-type bracket 41 shown in FIGS.6A to 6C. Further, in the above-mentioned embodiments, after the throughhole 62 is positioned with the jig 71, the second slits 26 and themid-transverse plane 38 are coincided with each other to properlyposition the bracket 61 to the outer surface of the tooth 74. Withoutthe second slits 26, the bracket 61 can properly be positioned on theouter surface of the tooth by coinciding the center of the bracket andthe FACC with each other in the same manner as a conventional method.

Still further, in the fourth embodiment, the through hole 62 is formedto the bracket 61. In place of the through hole 62, a projection or aconcave portion can be provided at the target point 27 of the bracket61, and then engaging one of them to a concave portion or a projectionformed at the FA point 73 of the tooth 74 in a row of teeth in advanceallows the target point 27 to directly be coincided with the marked FApoint 73. In this case, the cross-sectional shape of the projection orthe concave portion formed at the target point 27 of the base 22 of thebracket 61, and the cross-sectional shape of the concave portion or theprojection formed at the FA point 73 of the tooth 74 are not limited toround, but the shape may be rectangular or triangular. Further, theseprojections or concave portions are not required to be formed at theproduction of the bracket 61 or tooth in a row of teeth, but in theindirect boding method, it is sufficient to form the projections orconcave portions before the bracket is preliminarily bonded on a modelof the patient's row of teeth at a position where the bracket should bemounted.

The above-mentioned brackets according to the present invention areapplicable to all kinds of teeth including true molar teeth, and thepresent invention is applicable to brackets mounted on the tongue sidealso.

1. An orthodontic bracket characterized in that, a marker is provided onat least a portion of an outline that is generated by crossing a planeincluding a longitudinally extending center line, on a base of anarchwire slot, of said archwire slot and vertical to the base of thearchwire slot, and an outer surface of the body with each other.
 2. Theorthodontic bracket as claimed in claim 1, wherein said marker isselected from a protrusion, a projection, a slit and a notch.
 3. Anorthodontic bracket characterized in that, a through hole penetrates abody from a base of said body to an outer surface of said bracket alonga line passing through a point that is generated by crossing a line,which is generated by crossing a plane including a longitudinallyextending center line, on a base of an archwire slot, of said archwireslot and vertical to the base of the archwire slot, and the base of thebody, and a plane vertical to the center line of the archwire slot anddividing the body exactly into two parts.
 4. The orthodontic bracket asclaimed in claim 3, further comprising a marker provided on at least aportion of an outline that is generated by crossing the plane includingthe longitudinally extending center line, on the base of the archwireslot, of the archwire slot and vertical to the base of the archwireslot, and an outer surface of the body with each other.
 5. Theorthodontic bracket as claimed in claim 4, wherein said marker isselected from a protrusion, a projection, a slit and a notch.
 6. Anorthodontic bracket characterized in that, one of a projection and aconcave portion is provided at a point that is generated by crossing aline, which is generated by crossing a plane including a longitudinallyextending center line, on a base of an archwire slot, of said archwireslot and vertical to the base of the archwire slot, and the base of thebody, and a plane vertical to the center line of the archwire slot anddividing the body exactly into two parts.
 7. The orthodontic bracket asclaimed in claim 6, further comprising a marker provided on at least aportion of an outline that is generated by crossing the plane includingthe longitudinally extending center line, on the base of the archwireslot, of the archwire slot and vertical to the base of the archwireslot, and an outer surface of the body with each other.
 8. Theorthodontic bracket as claimed in claim 7, wherein said marker isselected from a protrusion, a projection, a slit and a notch.